Sugar-free candy, nutrition bars, cookies, cakes and other sweets might be sugar-free, but they do contain sugar substitutes, many of which can cause diarrhea, especially sugar alcohols. Artificial sweeteners such as aspartame and sucralose can also cause diarrhea in some people, but sugar alcohols are more likely to induce diarrhea. When you eat foods containing sugar alcohols, be aware that you might experience sudden, explosive diarrhea if you eat too much.